Fixed functions in pathfinding logic

I found those two inconsistencies while browsing the code. Someone familiar with the PathFinder and ObstacleCheck should have a look if I interpreted those functions correctly.
Take care with these and other changes you're making.  It's been quite a while, but I remember that these values were chosen due to the specific ways the pathfinding logic works, especially with the way the used nodes are cached.  I can't remember why but there was a reason for making this value 1.  I wish I had written some comments about it.